NEW YORK — Continuing anxiety over unemployment, personal debt and the housing market — compounded by the post-Christmas blizzard in the Northeast — limited December retail sales increases.

Continuing anxiety over unemployment, personal debt and the housing market — compounded by the post-Christmas blizzard in the Northeast — limited December retail sales increases.

Monthly same-store sales eased in the wake of November’s exceptionally strong promotional activity and an ongoing shift toward online shopping, according to Kantar Retail.

"It’s clear that November’s great in-store deals robbed spending from December," said Kantar senior economist Frank Badillo. "And in December shoppers were partial to spending online, perhaps encouraged even more by bad weather late in the month. One key exception was upscale department stores, which saw sales growth hold steady or improve in December."

For all of 2010 the pursuit of bargains led discounters to post a respectable 4% same-store sales increase, according to Racher Press research. Likewise, shoppers’ focus on the basics lifted same-store sales 3% at supermarkets and 2.6% at drug chains. Total sales rose 6% for discount stores, 5.4% for drug chains and 2.9% for supermarkets.

But the frugality of middle- and low-income shoppers hurt Target Corp. last month, as the retailer’s December same-store sales advanced less than one percentage point, well short of analysts’ ­expectations.

Based on quarter-to-date results and Target’s January outlook, the company continued to expect fourth quarter comparable-store sales would increase 2% to 4%.

Costco Wholesale Corp., meanwhile, again demonstrated its resilience, recording a 3% rise in U.S. same-store sales, excluding the impact of gasoline inflation and foreign currency gains. Total volume, including sales from the company’s Mexico joint venture, climbed 11% to $9.19 billion.

For its part, BJ’s Wholesale Club Inc. reported same-store sales edged up 1.4%, excluding the impact of gasoline. Traffic increased 2% (also excluding gasoline), and the average transaction amount was close to flat. Categories with the strongest sales included cheese, coffee, computers, dairy, deli, fresh bakery, health and wellness, meat, milk, prepared foods, produce, seasonal, video games, and wine; those with weaker sales included baby food, books, diapers, household chemicals, paper, plates/utensils and prerecorded video.